Why do you only need the first 4 letters of a BIP39 seed phrase?
Hardware wallets are an essential tool for anyone looking to invest in digital assets. These wallets store your private keys, which are used to access your crypto on the blockchain. You can think of it as a password. However, losing your private keys could mean losing access to your funds forever. A private key is a long string of characters that is difficult to store, type, or remember. This is where seed phrases come in.
What is a seed phrase?
A seed phrase, also known as a recovery phrase or mnemonic, is a series of words that is used to generate your private keys. These words are generated using a specific algorithm that ensures that they are unique and random. This is all done according to the Bitcoin Improvement Proposal 39 (BIP-39) . The seed phrase usually consists of 12, 18, or 24 words, and it is essential to keep it safe and secure.
Since these words come from an official, open-source, and industry-standard word list of only 2048 words, it becomes clear why you only need the first 4 letters of a seed phrase. Each word is unique after the first 4 letters. We'll go into more detail about this later.
The seed phrase should always be kept in the correct order. Don't change or delete words for "security purposes" thinking you'll remember it. History has shown that memorizing and splitting up seed phrases are the biggest causes of losing access to cryptocurrencies.
For example, a seed phrase might look like this. The example might even contain some words that are also in your seed phrase. But don't worry, there are countless different seed phrase possibilities .
hotel obvious agent lecture gadget evil jealous keen fragile before damp clarifyYou may have seen some of your seed words online somewhere. Of course, these were not your actual seed phrases, but they did come from an open-source, industry-standard word list. In the official BIP-39 word list, there are 2048 words. This list can be found on various websites, in physical copies, and in many other places online.
The official documentation of the BIP-39 protocol, from which the seed phrases originate, states the following about the word list:
“An ideal word list has the following characteristics:
a) Smart selection of words
- The word list is compiled in such a way that it is sufficient to type the first four letters to unambiguously identify the word.
b) Avoid similar words
- Word pairs such as "build" and "built", "woman" and "women", or "quick" and "quickly" not only make the sentence harder to remember, but are also more error-prone and harder to guess.
c) Sorted word list
- The word list is sorted, which allows for more efficient lookup of the codewords (e.g., implementations can use a binary search instead of a linear search).
- This also allows the use of a trie (a prefix tree), for example for better compression.”
How does a seed phrase work?
When you create a new wallet, you will be asked to write down your seed phrase. This phrase is used to generate your private keys, which are then used to access your funds. If you lose your private keys, you can recover your wallet using your seed phrase.
Seed phrases work by using a specific algorithm that generates a unique set of private keys. This algorithm uses a combination of your seed phrase and a random number generator to create your private keys. This means that your seed phrase is all you need to recover your wallet.
How to recover your wallet with a seed phrase?
If you lose your private keys, you can recover your wallet using your seed phrase. To do this, you will need to enter your seed phrase into a wallet that supports seed phrase recovery. The wallet will then use the algorithm to generate your private keys and give you access to your funds.
- Find your seed phrase. This can be stored on paper, digitally or preferably on a seed phrase backup .
- Reset your wallet to recover it.
- Start by entering the words in the correct order. Your wallet will autocomplete or suggest words in most cases. Remember, after the first 4 letters, each seed phrase word is unique.
- Once all the words are entered, your wallet will either confirm the seed words and grant you access, or indicate that the seed phrase is incorrect.
Why do I only need the first 4 letters of a seed phrase?
Seed phrases are a list of words, and each word is unique. However, you do not need to enter the entire word to recover your wallet. You only need to enter or save the first four letters of each word. This is the actual first four letters, not just the unique first four letters.
This is because the first four letters of each word are unique enough to identify the entire word. For example, if your seed phrase contains the word "elephant", you would only need to enter "elep" to recover your wallet. This makes recovering a seed phrase much easier and faster.
The BIP-39 protocol and the words in the dictionary were carefully chosen as common words that are unique after the first four letters. Consider this example:
Because all words are unique after the third letter, and your wallet knows the word list, it can autocomplete or suggest words.
Conclusion
Seed phrases are an essential tool for anyone looking to invest in cryptocurrencies. They provide an extra layer of security and ensure that you can always recover your wallet, even if you lose your private keys. Remember, it is crucial to keep your seed phrase safe and secure.
